The Scandinavian Defense is not often seen in games between two top players, although Carlsen famously beat Caruana with it. Arjun is used to taking risks to unbalance games against lower-rated players when the pressure to win with Black is greater. The variation itself is not that bad; suffice it to say that it has been played several times by Carlsen at different time controls. This line with 3...Qd6 is a specialty of GM Tiviakov, and it's not the first time that Arjun has played it.
1. e2e4  1... d7d5  2. e4d5  2... d8d5  3. b1c3 